Antiparasitic selecting system



Sem. 4, 3923. L L. LEVY ANTIPARASITIC SELECTING SYSTEM Filed Aug. 7.1920 2 Sheets-Sheet l Detecting high LUCIEN LEVY Inventor:

PW H. w, @W

Attorney.

Sept. L, w23. L L. LEVY ANTIPARASITIC SELECTING SYSTEM Filed Aug. 7,1920 2 SheeS-She? 2 LUCIEN LEVY Inventor:

'UuiraofsrATes i LUCIEN LEVY, or mms, FRANCE Patented Sept. 4, 1923.

. wasn PATENT ortica.

'ANrIrAaAsITIo sELEc'rING SYSTEM.-

Application-medaglia 7, 192e. Aseran nadamas.

vented .Improvementsin vAntiparasitic Selecting Systems, of which thevfollowing is a full, clear, and. exact description.

The present invention relates to an improvement in the" receivingselective device for electric k.waves lforming the subject-matter of thepatent application filed on Sep ten'iber 27th, 1919, under Sal'. No.326,993, and aims particularlyfat the separation of an electricalimpulse oflanyduration whatsoever and of Va short trainof waves of apredetermined frequency, vfrom a long train of waves of a predeterminedfrequency by means which -are easy to use'and to regulate.

-Such means consist essentially in im rovements in the artificiallinesthe utilization of whichI is provided for in the principal`invention. Furthermore, these improvements apply not only to theartificial lines, but also to the real lines and in eneral 'to' all systems overwhich waves gsuch as electrical, elastic, acoustic or the like)are adapted to be propagated and which arel capable of vii brating instationary waves for a predetermined frequency. `All these methods of'car-l rying out they invention permit of the im`v provement ofthe`working ofthe receiving and vselecting systems. V

vIn the new arrangements which constitute the subject matterof thepresent invention, the' well knownlfact is utilizedthat when a permanentorder of stationary waves isestablished,"the1energy appears along-theoscillating system inftwo" forms, one being kinetic and theotherpotential, themaxima of potential energy coinciding with the minima ofkinetic energyand vl'ce versa.

Under these* lconditions, the invention comprises a'methodWh'ichconsistsbroadly in arrangin-gatthose'points 1of the system where one of theenergies is minimum a. systeni `for absorbing this energy. It is evident1 that the consumption of energy `is feeble in a permanent stationarystate- On the contrary, during the variable 'state and for a freewavepropagating itself over'the system, the lossso'f en'ergy'willlbegreat, because half the energy ofthe wave "Will'give rise to :In theaccompanying drawings:

.Figure 1- shows-an improvedanti--parasitic receiving station=withafhigh selectivity for Figures 2, 3, 4 and 5 represent modificav tionsV'of detail. l

I'willnow proceed to describe by way'of example an application of thismethod tothe electrical lines. This application is representeddiagrammatically in the drawing annexed hereto and in'which Figure 1represents an arrangement of receiver'and se' lector pvovided with anartificial line of the im roved kind.

his arrangement is constituted veryv nearly1 like that represented inFigures 1 and leof' the patent application filed under Sal. No. 326,993;the same figures and reference letters denote the same parts.k 'Theamplifiers and the -local generator are reprel sented byvrectangleswithout redrawing 'the internal connections which are vindentical withIthose of this previous patent application.

In the new arrangement:

vAreaction coil 170 is coupled to a'coilv l 1685sh'unted through acondenser 169 and placed'in series with the oscillating circuit 2&3 soas`to reamplify the ultra-acoustic current by the lamps of the amplifier.-This reaction current might also be borrowed from the artificial line. Il f 2. The amplifier of mean and 'low frequency has been placed directlyat'theend of the artificial line. Y v3. Resistances 142, 143 arearranged in series in the artificial line and at the anti'- nodes oftension of the stationary wavesv develop therein 'the currents ofultra-acoustic fre uency to be selected. f

urthermore, resistances^ 140, y141 are placed in series'lwith theshunt'elements (they might alsofbe arrangeddirectly in shunt) atthenodes of potential. The resistances 142,143 have for example the value AL being the inductance ofthe coils 33 and C the capacity of thecondensers 34.`

Under these'conditions, it is fouhd as aAA matter of' fact that thefree'waves are very attenuated, as are in general, the stationary,waves, while only "the currents" 'of prede-l termined requency'to belselected pass with out attenuation in any considerabl'e degreeat nodes,that is to say it is advantageous to reduce the distributed losses ofthe line, due above all to the resistance of the self inductances. Theselosses which are small may be compensated by supplying energyto the lineat a sufiicently great number of points. For example the ultra-acousticcurrent amplified by the tube 53 of the principal invention may becaused to re-act at all the antinodes of tension on the shuntinductances by combining the circuits in such a way that the supply ofpower is the maximum for an impedance very much less than In Figure 2 isshown a modification of Fi re 1 in which the current of the oscillatingcircuit 93, 94 is caused to react on the artificial line.

Inductances 144 and 145 are arranged in this circuit in series with theinductance 93 and are coupled to the coils 33 corresponding theretoplaced at the antinodes of tension of the line;

In the Scheme of connections just described, the resistances introducedconsume power only to a very slight extent in permanent state and thisfact is due precisely to the fact that they are not distributedunlformly, but placed at determined points. On the contrary, thecompensating coils must be distributed as much as possible and coupledto the coils 33 with the suitable direction. The reaction will have onlyto furnish the losses of the line. Finally it is convenient to point outthat the resistanc'es may be advantageously replaced in thesearrangements by current limiting systems.

These systems when employed alone have the disadvantage of limiting thecurrent to a uniform value during the duration of a perturbation ofgreat amplitude.

On the contrary, by combining them with an inverse artificial line, thatis to say a capacity-inductance line, the duration of the limitation issmall and of the order of the half period of the predetermined frequencyto be selected, since the low frequencies `cannot ropagate themselvesover the line.

T e current limiting devices with two valves shown in Figure 3 betweenthe points G and H would replace a resistance placed between thesepoints. yIt is composed of two vacuum tubes 146, 147 having filaments148 and 150 heated by batteries 155 and 156. The filaments are connectedtogether by high resistances 153, 154 placed in series. The lates 149and 151 are connected to the positive ole of a battery of a few volts152.

The e ectrons can only issue from the for example lvalve and theresistance G, H becomes very reat.

It is possible to annul 152 or to change the direction of it, accordingto the value of limitation desired.

It is obviously possible to combine arrangements of the same kind withone or several vacuum tubes with three electrodes or several filamentswithout departing from the spirit of this part of the invention.

All the arrangements may be applied with advantage to the primaryselections or the secondary or tertiary selections made on the highfrequency, the ultra-acoustic frequency or the acoustic frequency.

Figure 4 shows how the method of damping free waves may be applied to avibrating string for the purpose of effecting the acoustic selectionmechanically.

A vibrating string 160 is stretched between the points K and L. 157 and158 represent devices capable of transforming electrical currents intomechanical vibrations (a telephone for example) and conversely. Forexample 157 is the transmitter and 158 the receiver, 157 being capableof being arranged at 104 (see Figure 1). 159 are dampers with bladesdippin into a liquid, placed at the nodes of vi ration of the string forthe frequency to be selected.

According to the l principle explained above, the free waves are greatldamped by the movements of the blades an the stationary wave ofpredetermined frequency is not so.

Figure 5 represents a method of carrying out the combination suggestedin the specification of the principal invention of receiving aerialswith artificial. lines.

This system is characterized by a special a-'angement of doubleartificial line, in which the series or shunt elements of each simpleline are coupled together magnetically.

The two ends of a frame 161, preferably of large dimensions, areconnected to two lines constituting the double line. This latter isconstituted for example by an inductance capacity line com osed of coils162, coupled ma netcally an arranged in series and of con e'nsers 163,arranged two by two in shunt, the points common to the condensers beingconnected to earth at 167 l'n continuation of the direct double line isa double inverse line, com osed of condensers 164 and coils 165, couplmagnetically two by two ceived.

and having their common points connected to earth. 'lhc arrow 166indicates the. direction of propagation of the wave to be re- Thisdouble bipolar line, artificial line, owing to the magnetic couplingstwo by two of the simple (artificial lines) direct and inverse lines,has not the same individual frequency and resonance when the currents(which 'circulate in the coils of each of the poles) are in phase ornot, so thatl if there is vexcitation by shock due to parasitic actionswhich are electrostatic or directed vertically, the oscillations willtake place on a frequency which is slightly different from that to whichit is tuned.

These. magnetically coupled lines may also be provided with all theapproved improvements for ordinary lines and serve for the primary,secondary or tertiary selections, and be placed at different points ofthe selecting systems. l

It is convenient to have a very close coupling between the coils 162 andbetween the coils 165. The two coils so coupled may be madesimultaneously by winding two insulated wires on one and the same cores,or by any other method.

The two last coils 165 are preferably wound in the reverse direction andcoupled to the oscillating circuit 2. 3.

In certain cases, the artificial line may be constituted in whole or inpart by a coil with a double winding the distributed capacity of the twowires being sufficient.

I claim 1. A method for antiparasitic reception of sustained wavescon'iprising the followingr operations: lropagating locally thesustained oscillatingr energy and the damped oscillatingr energy derivedrespectively from sustained waves and damped waves; producing stationarywaves with the sustained waves and free waves with ythe damped waves;absorbing the potential or the kinetic energy of the damped waveswithout absorbing the energy of the sustained waves, by means of thedifferent localization of these energies in the case of free waves andstationary waves; utilizing the energies after propagation lo controlthe indicating apparatus.

2. A process for separating sustained oscillatory energies from dampedoscillating energies consisting -in propagating locally several timesthe sustained land damped oscillatory energies, producing each timesta.- tionary waves from the sustained waves and free waves from thedamped Waves, absorbing the kinetic and the potential energies of thewaves at the points of minimum 'energy in permanent operation withstationary waves, and utilizing the energies after propagation forcontrolling indicating apparatus.

A process for separating sustained oscillatory energies from dampedoscillatory vthe receiving frequency, .propagating locally the dampedand undamped secondary currents in such a way that the damped secondarycurrents give free waves and the sustained secondary currents givestationary waves, absorbing the kinetic and the potential energies ofthc waves at the points of minimum energy in permanent operation ofstationary waves, and utilizing the lenergies after propagation forcontrolling indicating apparatus.

4. A process which consists in propagating locally and selectively thesustained and damped oscillatory energies derived from the sustained anddamped waves, producing stationary waves from the sustained waves andfree waves from the damped waves, amplifying the energies afterpropagation, supplying a part of this amplified energy at several pointsof the local wave propagating system so as to obtain a perfectstationary wave. absorbing the kinetic and potential energies of thewaves at the points where these energies are minimum in permanentoperation of stationary Waves,and utilizing the energies afterpropagation for controlling indicating apparatus.

5. A process which consists in transforming the currents, arising fromthe electric received waves, in a succession of currents of locallydetermined frequency a number of which are ultra acoustical; propagatingseveral times the undamped and damped electric oscillatory energies, ofultra-acoustical frequency, respectively arising from the sustainedWaves and from the damped parasitic Waves; absorbing the potential andthe kinetic energy of the damped waves without absorbing the energy ofthe sustained waves, by means of the different 1ocalizationy of theseenergies in the case of free and stationary waves; utilizing theenergies after propagation for controlling indicating apparatus.

6. A process which consists in transforming the primary currentsreceived, in currents of adjustable. ultra-acmlstical secondaryfrequency locally generated by production of beats between the receivedcurrents and a high frequency current locally -generated and detectionof these beats; propagating locally the undamped and damped currents ofultra-acoustical secondary frequency, respectively arising from thetransformation of the damped and sustained currents received; producingstationary Waves from the sustained waves and free waves from the dampedwaves; absorbing the potential or the kinetic energy of the damped waveswithout absorbing the energy of the sustained wares by means of thedifferent localizations of these energies in the case otl 'free andstationary vaves; utilizing the the influence of the latter and having asutii,

cicntly large number ot' elements for causing the short wave-train togive therein only a free wave-and rcsistances in series in theartificial line at the nodes of current and in shunt at the nodes ofvoltage of the stationary wave.

8. In a receiving selective system in combination with radio devices, anadjustable artificial electric line tuned to the frequency of thecurrents to be selected, vibrating in stationary waves and provided withresistances in series inthe line at the nodes of current and in shunt atthe nodes of voltage of the stationary wave.

9. A device of reception with multiple selections comprising: A primaryartificial line tuned to the frequency of the Waves received; a localgenerator of high frequency;

an ampliier-detector with vacuum tubes;

means for coupling the latter to the primary artificial line; asecondary artificial line tuned to the secondary frequency; means forcoupling this secondary artificial line to the last circuit of theamplifier' of high frequency; an amplifier-selector detector means forcoupling the latter to the secondary selector, and a receivingapparatus, for instance a telephone, actuated by the current of the lastcircuit of this second amplifier.

10. In-a receiving selective system for electric waves, a devicepermitting the separation of a long wave-train from a short wavetrain,coinprlsing: An artificial electric line tuned to the frequency of thelong wave-train, vibrating in stationary Waves under the influence ot'the latter and having a sufficient number of elements for causing theshort Wave-train to give therein only a free Wave; and thermionicenergy-limiters comprising two thermionic valves arranged in series inreverse directions, the said energy-hunters being in series in theartificial line at the nodes of current and in shunt at the nodes ofVoltage of the stationary Wave.

The foregoing specification of my Improvements in anti-parasiticselecting system signed by me this 17th day of July, 1920.

LUCIEN LEVY.

